ASCA and BeppoSAX results have demonstrated that
X-ray Observations of Seyfert galaxies are important to i)
verify the predictions and, thus, validity of unified models
and ii) understand the origin of the X-ray background.
However, average intrinsic properties and "true" column
density distribution of Seyfert galaxies obtained from an
unbiased sample, the most crucial points in issues i) and
ii), are still lacking at present. We therefore show how an
XMM study (250 ks awarded in the EPIC GT) on a well-defined,
complete, and statistically significant sample of the
nearest known 27 Seyfert galaxies could fill this lacuna.
Moreover, this study will allow a comprehensive study of the
serendipitous source populations in the host galaxies and in
the fields.

The author(s) of this abstract have provided an email address
for comments about the abstract:
mcappi@tesre.bo.cnr.it